For decades, suspended ceilings have been installed in commercial and private buildings as a relatively quick, efficient, and inexpensive alternative to traditional beam and sheetrock ceilings. Most suspended ceilings are formed from a grid of suspended metal spars that intersect to define square or rectangular framed sections into which lightweight ceiling panels are placed to complete the ceiling. In most suspended ceiling structures, the metal spars are formed with an inverted T-shaped cross-section that defines upstanding ridges extending longitudinally along the centers of the spars. Thus, the spars along the sides of each bounded section of the suspended grid define a bounded frame that receives, aligns, and supports a ceiling panel.
Over the years, numerous types of fixtures have been designed to be installed in the framed sections of suspended ceilings. For example, florescent light fixtures, surveillance camera domes, and loud-speaker panels have all been developed to fit within selected frame sections of a suspended ceiling structure to provide light, surveillance, music, and other amenities within a building.
In most modern buildings with suspended ceiling structures, the heating and air conditioning main supply and return ducts are also disposed, along with light fixtures, plumbing, and the like, above the level of the suspended ceiling. In these types of installations, the main supply and return ducts usually communicate with the interior of a room through vent and duct assemblies that, like florescent light fixtures, are sized to be received and supported within a framed section of the suspended ceiling structure. While these types of vent and duct assemblies have proven to be attractive and efficient in buildings with suspended ceilings, their assembly and installation can be and often is time consuming and frustrating for an installer. For example, some prior art vent and duct assemblies have been shipped in pieces and have required assembly prior to their installation within the suspended ceiling. Once assembled, the vent and duct assembly usually is manually positioned within a framed section of the suspended ceiling grid within a few feet of a main supply or return duct.
With the vent and duct assembly in place, the distance between the vent and duct assembly and the main supply duct is measured or estimated and a length of rigid or flexible duct is cut to be extended between the vent and duct assembly and the main supply or return duct. The cut flexible duct is then secured at one end to the vent and duct assembly and at its other end to the main supply or return duct. The vent and duct assembly is thus coupled to the heating and air conditioning system and serves as a conduit for circulating air within the room.
The installation of vent and duct assemblies as just described, while acceptable, has nevertheless been wrought with various problems and shortcomings inherent in the design of prior art vent and duct assemblies. For example, the sizing and cutting of flexible duct to extend between the assembly and main supply or return duct must be done very accurately to ensure proper fit and air flow. If the flexible duct assembly is cut too long, for example, it will tend to sag between its ends so that airflow becomes restricted. On the other hand, if the flexible duct is cut too short, it will tend to kink or collapse at its connection points to the main supply duct or to the vent and duct assembly, similarly restricting the flow of air through the assembly.
Even when the flexible duct is measured and cut to the proper length, its installation still can generate problems for a workman. For example, the flexible duct, once cut, is usually fastened to the vent and duct assembly and then stretched lengthwise to meet and be coupled to the main supply or return duct. Many times when the flexible duct is being stretched, the forces imparted to stretch the duct are sufficient to raise the vent and duct assembly out of position within the suspended ceiling grid so that the vent and duct assembly can become dislodged or even fall through the ceiling grid. Accordingly, the installation of these prior art vent and duct assemblies has often required two workers, one to hold the assembly and the other to stretch and connect the flexible duct.
It can thus be seen that installation of prior art vent and duct assemblies in suspended ceilings has been an inefficient, time consuming, and sometimes frustrating process for the installers. Furthermore, in very large buildings where hundreds of such assemblies must be installed, the total time required to install each assembly often necessitates additional installation crews to complete the job within schedule.
Accordingly, a continuing and heretofore unaddressed need exists for a vent and duct assembly that can be installed within a suspended ceiling quickly and easily by a single installer, that does not require preassembly, does not require the sizing and fitting of flexible duct between the assembly and the main supply or return duct, and that, once installed in the ceiling grid, is held firmly in place and does not become dislodged or fall through the grid during the installation process. It is to the provision of such a vent and duct assembly that the present invention is primarily directed.